Metal melting apparatus

Abstract

A refractory well ( 16 ) for melting scrap metal pieces into a molten metal bath, comprises an inlet ( 18 ) for introducing metal into said well, the inlet being located so as to cause a circular flow of molten metal in said well, an outlet ( 19 ) for the flow of metal from said well and an electromagnetic pump ( 22 ) located beneath the refractory well for pumping said molten metal from said well through said outlet.

The invention claimed is: 
     
       1. A refractory well for melting solid scrap metal pieces into a molten metal bath, comprising:
 an inlet for introducing the molten metal into said refractory well from the molten metal bath, said inlet being located so as to cause a circular flow of the molten metal in said refractory well; 
 an outlet for the flow of the molten metal from said refractory well; 
 an electromagnetic pump located beneath the refractory well for pumping said molten metal from said refractory well through said outlet; and 
 a bypass conducting a portion of the molten metal past said outlet, said bypass being arranged so as to enable heat transfer from the molten metal in said bypass to said refractory well at or adjacent said outlet thereby to minimize the risk of blockage of solid metal scraps in said outlet, the refractory well defining a cavity. 
 
     
     
       2. A refractory well as claimed in  claim 1 , wherein the electromagnetic pump is located so as to apply a force to the molten metal downstream of at least one of said inlet and said outlet thereby to draw the molten metal through said well. 
     
     
       3. A refractory well as claimed in  claim 1 , wherein an outlet passage connects with said outlet and the electromagnetic pump is located adjacent the outlet or outlet passage of said refractory well. 
     
     
       4. A refractory well as claimed in  claim 1 , wherein an outlet passage connects with said outlet and the electromagnetic pump is located vertically below at least one of the outlet and outlet passage of said refractory well. 
     
     
       5. A refractory well as claimed in  claim 1 , wherein the inlet is arranged to direct molten metal into said well tangentially thereof so as to create a vortex in said molten metal in said well. 
     
     
       6. A refractory well as claimed in  claim 5 , wherein the inlet is formed as an elongate opening extending at least a portion of the height of the cavity defined in the refractory well. 
     
     
       7. A refractory well as claimed in  claim 5 , wherein the inlet is formed as an elongate opening extending from adjacent the base of the cavity defined in the refractory well. 
     
     
       8. A refractory as claimed in  claim 5 , wherein the inlet is formed as an elongate opening extending the height of the cavity defined in the refractory well. 
     
     
       9. A refractory well as claimed in  claim 5 , wherein the outlet is formed as a horizontal rectangular slot located at or adjacent the bottom of said cavity defined in the refractory well. 
     
     
       10. A refractory well as claimed in  claim 5 , wherein the outlet is formed as a horizontal rectangular slot located adjacent the base of said cavity defined in the refractory well. 
     
     
       11. A refractory well as claimed in  claim 5 , wherein the outlet is formed as a horizontal rectangular slot opening into a side wall of said cavity defined in the refractory well. 
     
     
       12. A refractory well as claimed in  claim 5 , wherein the outlet extends downwardly from the base of said cavity defined in the refractory well. 
     
     
       13. A refractory well as claimed in  claim 1  wherein said outlet and said bypass open into said outlet passage adjacent one another. 
     
     
       14. A refractory well as claimed in  claim 1  wherein said outlet is formed in a lower wall of said refractory well opening into said outlet passage and said bypass is formed by said inlet extending across said wall and opening into both said well and said outlet passage. 
     
     
       15. A method of melting scrap metal comprising:
 providing a refractory well having an inlet for introducing molten metal into said refractory well and an outlet for the flow of molten metal from said refractory well, and an electromagnetic pump located beneath the refractory well for pumping said molten metal from said refractory well through said refractory well outlet; 
 causing a downward, circular flow of the molten metal in said refractory well towards said outlet of said refractory well; 
 introducing solid scrap metal into said molten metal flow; 
 applying a pumping force to said molten metal at a location thereby to cause said molten metal to be drawn and not pushed through said outlet; and 
 conducting a portion of the molten metal through a bypass past said outlet, so as to enable heat transfer from said molten metal in said bypass to said refractory well at or adjacent said outlet thereby to minimize the risk of scrap metal blockage in said outlet. 
 
     
     
       16. A method as claim in  claim 15 , wherein the pumping force is applied by an electromagnetic pump that is located so as to apply a force to said metal downstream of at least one of said inlet and said outlet thereby to draw said metal through said well. 
     
     
       17. A method as claimed in  claim 15 , wherein the pumping force is applied by an electromagnetic pump and wherein an outlet passage connects with said outlet and the electromagnetic pump is located adjacent the outlet or outlet passage of said well. 
     
     
       18. A method as claimed in any of claims  claim 15 , wherein the pumping force is applied by an electromagnetic pump and wherein an outlet passage connects with said outlet and the electromagnetic pump is located vertically below at least one of the outlet and outlet passage of said well. 
     
     
       19. A method as claimed in any of claims  claim 15  comprising directing molten metal into said well tangentially thereof so as to create a vortex in said metal in said well. 
     
     
       20. A method as claimed in  claim 19 , comprising directing molten metal into said refractory well tangentially thereof along at least a portion of the height of the cavity defined in the refractory well. 
     
     
       21. A method as claimed in  claim 19 , comprising directing molten metal into said well tangentially thereof adjacent the base of the cavity defined in the refractory well. 
     
     
       22. A method as claimed in  claim 19 , comprising directing molten metal into said well tangentially thereof over the height of the cavity defined in the refractory well. 
     
     
       23. A method as claimed in  claim 15 , wherein the outlet is formed as a horizontal rectangular slot located at or adjacent the bottom of said cavity defined in the refractory well. 
     
     
       24. A method as claimed in  claim 15 , wherein the outlet is formed as a horizontal rectangular slot located adjacent the base of said cavity defined in the refractory well. 
     
     
       25. A method as claimed in  claim 15 , wherein the outlet is formed as a horizontal rectangular slot opening into a side wall of said cavity defined in the refractory well. 
     
     
       26. A method as claimed in  claim 15 , wherein the outlet extends downwardly from the base of said cavity defined in the refractory well. 
     
     
       27. A method as claimed in  claim 15  wherein said outlet and said bypass open into said outlet passage adjacent one another. 
     
     
       28. A method as claimed in  claim 27  wherein said outlet is formed in a lower wall of said refractory well opening into said outlet passage and said bypass is formed by said inlet extending across said wall and opening into both said well and said outlet passage.